Image processing systems are known which may include for example, when implemented in the form of a laptop computer or handheld device, a central processing unit and graphics accelerator (e.g. graphics co-processor) and frame buffer memory that stores image frames of data that are displayed on a display screen. Many types of display devices require image processing to convert the image data from industry standard formats to the format required by the specific display technology. For example, LCD displays may require gamma correction, color temperature adjustment, dithering, scaling, edge enhancement, frame rate conversion, deinterlacing of interlaced fields or frames and pixel intensity overdrive compensation to reduce pixel switching times, among other processes. Plasma displays may require other specific operations and other types of displays may require yet other operations. For example, digital light projection (DLP) televisions, LCD displays for televisions, plasma displays for televisions and other display types attempt to emulate the exact properties of a cathode ray tube (CRT) but they not are cathode ray tubes and as such require additional image processing that is specific to the display type.
Image processing operations may require a frame (or more than one frame) of storage of previous image data. For example, frame rate conversion, deinterlacing, and pixel intensity overdrive compensation to reduce pixel switching times may require the use of a current image frame and previous image frames. Another class of image processing may need only image data from a current frame to produce its output. Currently some of the display systems that perform the second class of operations (no frame storage) are done either in a graphics co-processor before sending the image over a display interface, such as dithering, while others are done in specialized electronics integrated within the display unit.
Typically, frame storage operations that require the storage of one or more frames of previous image data are not performed on the graphics accelerator side of the display interface but are typically performed by specialized electronics that are integrated within the display unit and may include for example another frame buffer and image processor because each type of display unit may need to perform different types of display specific operations. These operations may require relatively expensive electronics in the display device itself.
Graphics co-processors are known to provide temporal processing such as field deinterlacing for interlaced television signals. However, such processing occurs prior to any display specific processing and is display type independent.
Graphics co-processors are also known to provide scaling, gamma correction, and dithering operations on information which typically does not require retrieving of information from a frame buffer and is typically done prior to sending to the display device that then has its own internal logic and frame buffer for providing display type specific processing.
As such, it would be desirable to provide an image processing system that eliminated or reduced the need for use of a frame buffer in the display unit and eliminate or reduce the need for such processing to be present in the display device so that relatively expensive electronics in the display may be reduced or eliminated.